rt

#include<iostream>
#include<cstdio>
using namespace std;
typedef long long ll;
ll n;
int main()
{
    scanf("%lld",&n);
    double l=0,r=n+1;
    while(l+1<r)
    {
        double m=(l+r)/2;
        if(m*m*m>n)
            r=m;
        else
            l=m;
    }
    ll as=r;
    printf("%lld",as);
    return 0;
}